The present invention relates to rotary sprinklers, and particularly to ball-type rotary sprinklers in which the sprinkler is rotated in a series of stepped increments by impacting one or more balls against an abutment carried by the sprinkler.
The conventional ball-type rotary sprinklers generally include a swirl chamber containing one or more balls which are driven around the chamber by the water flowing from the sprinkler inlet to the sprinkler outlet to produce the impacts rotating the sprinkler. Since in such a sprinkler the ball is in the flowpath of the water, the ball imposes a resistance to the flow of the water through the sprinkler. Moreover, dirt within the water may settle in the swirl chamber and/or on the ball, thereby making the sprinkler susceptible to jamming.